Isolation, Identification, and Analysis of the Genetic Characteristics of Human Rotavirus of G3P10 Genotype

Group A rotavirus remains a major pathogen causing infantile diarrhea. Although rotaviruses are known for their zoonotic potential and frequent genomic reassortment, the virological features of newly isolated strains and their suitability as vaccine candidates remain unclear. In this study, a human rotavirus strain of genotype G3P[10] was isolated from the fecal sample of an infant with diarrhea in Xiangyun County, Yunnan Province, China in 2019, and subsequently cultured in MA104 cells in 2021. The strain was designated XYR-19. Its biological characteristics were assessed through morphological examination, serological testing, and molecular analyses. Whole-genome sequencing and bioinformatic approaches were then used to define its genetic profile. Similarly, an inactivated vaccine was prepared based on this strain and evaluated its immunogenicity. Biological characterization confirmed that XYR-19 demonstrated stable structural and replication properties, reaching a viral titer of 7.3 lg CCID₅₀/mL after propagation. Whole-genome sequencing revealed a genotype constellation of G3-P[10]-I8-R3-C3-M3-A9-N3-T3-E3-H6. Comparative analysis indicated that the VP4 and VP7 genes shared 99.41% and 96.57% nucleotide identity, respectively, with the circulating domestic strain bat-derived strain MYAS33, while also harboring distinct mutation sites. Phylogenetic analysis showed that XYR-19 clustered closely with human RVA strain MS2015-1-0001, CMH079, and CMH-S015-19. These findings expand current knowledge of rotavirus epidemiology in the region and provide essential data for tracking local transmission dynamics. Moreover, they offer a valuable basis for future rotavirus vaccine development and for designing strategies aimed at limiting cross-species transmission, ultimately supporting improved prevention and control of infantile diarrhea in the area.